It is that if it says Bits, it is because it is only BITs, The bit, in other words, is a digit. Unlike the decimal system, which uses ten digits (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9), the binary system appeals to only two (0 and 1). A bit, therefore, can represent one of these two values (0 or 1).